That's why I was looking at just the 20 minutes of each day when demand peaks. It wouldn't be homogeneous across time. For instance demand from 2 AM will be less than 5 PM.
However, any real distribution that's similarly shaped at all, whether Gaussian, normal, weibull or some other bell-shaped blob, the point is that the larger scale system will experience lower probability of overload for a given average capacity factor. The extreme case of this in my 70% capacity factor example is a one-stall station with on average a 70% chance of being used. Such a station would have a wait time very often.
So, making the supercharger network bigger benefits all participants including Tesla owners.